Function competitive_hpp::prelude::enumerate

pub fn enumerate<I>(iterable: I) -> Enumerate<<I as IntoIterator>::IntoIter> where
    I: IntoIterator, 

Iterate iterable with a running index.

IntoIterator enabled version of .enumerate().

use itertools::enumerate;

for (i, elt) in enumerate(&[1, 2, 3]) {
    /* loop body */
}